Such electrical conductors are known and are usually in the form of a grid of heating wires extending between conductive strips, for example as described in GB Pat. No. 972,453 and GB Pat. No. 1,183,316. In another construction the conductors may be conductive strips and a heating film coated onto the glass surface and extending between the conductive strips.
It is common practice for automobile windshields to have an obscuration band which is usually black, fired to a marginal band of the windshield. In a laminated windshield this band is usually carried around the margin of the inner surface of the inner glass sheet, that is the surface of the glass which is exposed inside the vehicle when the windshield has been fitted. This obscuration band hides from external view the flange on the car frame to which the windshield is usually adhered, and hides any adhesive or any other securing means which lie behind the periphery of the windshield. When manufacturing a laminated windshield the obscuration band is painted onto the appropriate glass surface when the glass is cold and is fired onto that surface when the glass passes through the sag bending furnace as one of a pair of glass sheets which are sag bent together prior to lamination.
During sag bending the surface of the glass which carries the obscuration band has to be uppermost in order to avoid problems with smudging or sticking of the paint. Since it has been customary to laminate the glass sheets together in the same order as that in which they are sag bent, this is not inconvenient since it results in the obscuration band being carried on the inner surface of the windshield.
GB Pat. No. 2,078,169 discloses reversing the order of two glass sheets after bending and before laminating in cases where the sheets have different physical-chemical properties and/or different thicknesses. There is no disclosure in GB Pat. No. 2,078,169, however, of the provision of electrical conductors and obscuration bands.
When electrical conductors are incorporated in the laminate they are usually carried between one of the glass sheets and the interlayer. Conventionally therefore the conductive strips extending along opposite edges of the windshield, usually near the top and bottom of the windshield, are not obscured from external view by the obscuration band.